Method of making gear-wheels.



' H0. 874,448. YEETEHTED HEazE, 19o?.

W. H. SMITH. METHonoE MAKING GEAR WHEELS. APPLIUATIN FILED AUG. 8, 1906.

IJ E f No. 874,448.

WfHsMITH. MBTHODFHMAKING GEAR WHEELS'.

APPLICATION FILED AUG. 8, 1966.

PATENTED DEG. V2li, 1907.

' UNrrnn STATE-.s PATENT onirica. s

WILLIAM II. SMITH., OF BUFFALO, NEW YORK, ASSIGNOR OF ONILHALF TO JOHN KEIM MILLS, INC., OF IUFFALO, NEW YORK, A CORPORATION OF NEW YORK.

METHOD OF MAKING GEAB--YI-IIEELS.v

Specification of Letters Patent.

Application filed August 8, 190%. Serial No. 329.666.

T 0 all 'zi/)7mm it may concern.'

Be it known that I, VJILLIAM li. Snrrn, a

citizen of the United States, residing at Buffalo, in the county of Erie and State of New York, have invented a new and usefullinprovement in lvlethods of Making Gear- Wheels, of wlnch the follownig 1s a specificathe same which necessarily caused the gear wheel when in useto wear rapidly. Hardening of the gear wheel after being cut is not permissible inasmuch as this has a tendency to distort the teeth and render the same inaccurate.

In order to increase the wearing capacity of gear wheels it has been proposed to forge them of very hard metal which method however is impracticable for producing perfect gear wheels because of the imperfections in the forging and the diflculty of grinding or cutting the teeth so that they will run smoothly and noiselessly. f

The object of this invention is to produce perfect running and durable gear wheels expeditiously and at comparatively low cost.

In the accompanying drawings consisting of two sheets: Figure 1 is a sectional elevation of one form of a press which is suitably constructed for practicing my invention and showing the teeth swaging dies in their projected or operative position. Fig. 2 is ahorizontal section of the same in line 21-2 Fig. l. Fig. 3 is a fragmentary horizontal section, on

van enlarged scale, in line 3-3 Fig. 1 but showing the teeth swag-ing dies retracted into their inoperative position. Fig. 4 is a frag mentary horizontal section, on an enlarged scale, in line 4 4 Fig. 1 showing part of the means forejecting the iinished gear wheel from the press. Fig. 5 is a detached bottom plan view'of the endwise swaging punch.

Similar'letters of` reference refer to like parts in the several figures.

In practicing my invention, a circular or cylindrical blank of approximately the size of the gear wheel desired is first cast forged or otherwise formed of metal which when' cool is very hard and has the capacity of resisting wear to a great extent. then heated sul'liciently to render the same more pliable and capable of'being swaged into desired shape under pressure. thns heated the blank is subjected to the pressure of an annular row of radially movable dies which are operated to sin1ultaneously press against thev entire periphery of the blank and swage or displace the metal of the sameso as -to produce an annular row of gear teeth thereon the n )ygrking faces `of which are iinished and run vsiiiothly and noiselcssly in mesh with the teeth of other gear wheels which have teeth of equally perfeet construction. vAfter the teeth have been thus formed and finished. on the blank the same is subjected to pressurein a direc-v tion lengthwise of its axis so as to condense the metal and swage the same outwardly sulliciently to fully`engage the teeth forming dies and produce teeth having f ull and uniform bearing surfaces.

T he apparatus for practicing my improved method of making gear wheels may be variously constructed, that shown in drawings, for example, being suitable forthe purpose and constructed as follows:

A represents the base or bed of a stamping or swaging press or machine which is rovided centrally on -its upper side Wit i a ,pocket which has a flat bottom B and a cyindrical side wall C, and is normally open at the top to permit of inserting the gear blank D axially into the pocket or removing the same therefrom. T iis blank may be either a" solid cylinder or the samemay be rough'cast forged, or otherwise formed n ith an annular row of partly formed or unfinished gearteeth This blank is' While d on its periphery, as shown in Fig. 2,' so as to approximate its finished form and reduce the nork of the machine in putting it into finished condition. The gear blank is preferably centered in the pocket by means of an upwardly projecting stud E arranged centrally from the bottom of the pocket and entering` the bore e of the gear blank.

F represents a plurality ofradially inovable slides provided at their inner ends with diesf which are constructed to vforirriinished gear teeth o'n vthe periphery of the blank. These slides are guided in equidistant radial 

